The vast majority of high voltage transmission conductors used includes strands of high strength steel surrounded by multiple strands of aluminum wire. The steel strands are the principle load bearing component holding up the wire, while the softer, more elastic aluminum strands include the majority of the electrical power transport component. Many variations of transmission wire operating at between approximately 115 kv to 800 kV involve this basic design concept and have these two basic components.
More recently, a composite core conductor having a fiberglass and epoxy resin core covered by aluminum wire has emerged as a substitute for the steel support stranding in high voltage transmission conductors. However, the outer surface of the composite core is difficult to mechanically connect to a compression tube of a connector member. The outer surface of the composite core is sensitive, such that a scratch on the outer surface can lead to a fracture of the composite core. Due to the sensitivity of the composite core, composite core conductors are not crimped and are usually connected with wedge connectors such as is disclosed in U.S. Pat. No. 7,858,882 to De France, which is hereby incorporated by reference in its entirety. Accordingly, a need exists for an electrical connector in which a composite core conductor is crimped thereto without damaging the outer surface of the composite core.
A conventional crimp die 2 is shown in FIGS. 1-3. A plurality of planar surfaces 3 form a crimp surface of the die 2. For example, the crimp surface of each conventional die 2 is comprised of three planar surfaces 3, as shown in FIG. 3. The planar surfaces 3 form a substantially hexagonal crimping area during the crimping process and result in a gap 4 between the dies 2 and a tubular portion 5 in which the composite core 26 is disposed, as shown in FIG. 2. The resulting gap 4 can detrimentally affect the outer surface of the composite core 26 as the crimp is not completely controlled. Additionally, the planar surfaces 3 provide a smaller area of compression 65 between the planar crimp surfaces 3 and the outer surface of the tubular portion 5 in which the composite core 26 is disposed. Furthermore, the planar surfaces 3 of the crimp die 2 apply compressive forces on tubular portion 5 at angles of 31 degrees from a horizontal axis 6 through a center of the core 26 and vertically at 90 degrees from the horizontal axis 6, as shown in FIG. 1. Three areas of compression are formed with each die 2. Accordingly, a need exists for a crimp die providing better crimp control of a composite core conductor.